math.h(3HEAD) Headers math.h(3HEAD)NAME
math.h, math - mathematical declarations
SYNOPSIS
#include <math.h>
DESCRIPTION
The <math.h> header includes definitions for the following types:
float_t A real-floating type at least as wide as float.
double_t A real-floating type at least as wide as double, and at
least as wide as float_t.
If FLT_EVAL_METHOD equals 0, float_t and double_t are float and double,
respectively. If FLT_EVAL_METHOD equals 1, they are both double. If
FLT_EVAL_METHOD equals 2, they are both be long double. Other values of
FLT_EVAL_METHOD are implementation-defined.
The <math.h> header provides the following constants. The values are of
type double and are accurate within the precision of the double type.
M_E The base of natural logarithms (e).
M_LOG2E The base-2 logarithm of e.
M_LOG10E The base-10 logarithm of e.
M_LN2 The natural logarithm of 2.
M_LN10 The natural logarithm of 10.
M_PI , the ratio of the circumference of a circle to its
diameter.
M_PI_2 /2.
M_PI_4 /4.
M_1_PI 1/.
M_2_PI 2/.
M_2_SQRTPI 2 over the square root of .
M_SQRT2 The positive square root of 2.
M_SQRT1_2 The positive square root of 1/2.
The <math.h> header defines the following symbolic constants:
MAXFLOAT The maximum value of a non-infinite single-precision
floating point number.
HUGE_VAL A positive double expression, not necessarily repre‐
sentable as a float. Used as an error value returned by
the mathematics library. HUGE_VAL evaluates to +infin‐
ity on systems supporting IEEE Std 754-1985.
HUGE_VALF A positive float constant expression. Used as an error
value returned by the mathematics library. HUGE_VALF
evaluates to +infinity on systems supporting IEEE Std
754-1985.
HUGE_VALL A positive long double constant expression. Used as an
error value returned by the mathematics library.
HUGE_VALL evaluates to +infinity on systems supporting
IEEE Std 754-1985.
INFINITY A constant expression of type float representing posi‐
tive or unsigned infinity, if available; else a posi‐
tive constant of type float that overflows at transla‐
tion time.
NAN A constant expression of type float representing a
quiet NaN. This symbolic constant is only defined if
the implementation supports quiet NaNs for the float
type.
The following macros are defined for number classification. They repre‐
sent the mutually-exclusive kinds of floating-point values. They expand
to integer constant expressions with distinct values
FP_INFINITE
FP_NAN
FP_NORMAL
FP_SUBNORMAL
FP_ZERO
The following optional macros indicate whether the fma() family of
functions are fast compared with direct code:
FP_FAST_FMA
FP_FAST_FMAF
FP_FAST_FMAL
The FP_FAST_FMA macro is defined to indicate that the fma() function
generally executes about as fast as, or faster than, a multiply and an
add of double operands. The other macros have the equivalent meaning
for the float and long double versions.
The following macros expand to integer constant expressions whose val‐
ues are returned by ilogb(x) if x is zero or NaN, respectively. The
value of FP_ILOGB0 is either {INT_MIN} or -{INT_MAX}. The value of
FP_ILOGBNAN is either {INT_MAX} or {INT_MIN}.
FP_ILOGB0
FP_ILOGBNAN
The following macros expand to the integer constants 1 and 2, respec‐
tively:
MATH_ERRNO
MATH_ERREXCEPT
The following macro expands to an expression that has type int and the
value MATH_ERREXCEPT:
math_errhandling
The value of the macro math_errhandling is constant for the duration of
the program. If a macro definition is suppressed or a program defines
an identifier with the name math_errhandling, the behavior is unde‐
fined.
The <math.h> header defines he following external variable:
extern int signgam;
The <math.h> header defines the structure and constants used by the
matherr(3M) error-handling mechanisms.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOintro(3), fenv.h(3HEAD), libm(3LIB), limits.h(3HEAD), matherr(3M),
attributes(5), standards(5)SunOS 5.10 11 Aug 2004 math.h(3HEAD)
